regulator: qpnp-labibb: move TTW mode enter/exit out of suspend/resume

Currently, if the TTW mode is enabled, register settings are
being configured when the regulator driver's suspend callback
is invoked. This is little late given the time constraints
especially when the regulator is disabled and suspend operation
finishes up after several seconds. Instead of that, configure
the TTW mode settings when the regulator is disabled. Normal
mode settings will be applied again when the regulator is
enabled.

CRs-Fixed: 847094
Change-Id: I7699ceffca8091e4082382f392e40100d39dc7bb
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>